Submission #898681

#	Time	Username	Problem	Language	Result	Execution time	Memory
898681		math_rabbit_1028	Fibonacci representations (CEOI18_fib)	C++14	50 / 100	4057 ms	1512 KiB

fib

#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
ll MOD = 1e9 + 7;

int n, arr[101010];
ll dp[101010];

vector<int> one(vector<int> vec) {
    vector<int> ret;
    while (true) {
        int f = 0;
        for (int i = 2; i < vec.size(); i++) {
            if (vec[i-1] + 1 == vec[i]) {
                f = i;
                break;
            }
        }
        if (f == 0) break;
        for (int i = 0; i < vec.size(); i++) {
            if (i == f || i == f-1) continue;
            ret.push_back(vec[i]);
        }
        ret.push_back(vec[f]+1);
        sort(ret.begin(), ret.end());
        vec = ret;
        ret.clear();
    }
    return vec;
}

vector<int> zero(vector<int> vec) {
    vector<int> ret;
    while (true) {
        int f = 0;
        for (int i = 2; i < vec.size(); i++) {
            if (vec[i-1] == vec[i]) {
                f = i;
                break;
            }
        }
        if (f == 0) break;
        for (int i = 0; i < vec.size(); i++) {
            if (i == f || i == f-1) continue;
            ret.push_back(vec[i]);
        }
        if (vec[f] == 1) ret.push_back(2);
        else if (vec[f] == 2) { ret.push_back(1); ret.push_back(3); }
        else { ret.push_back(vec[f]-2); ret.push_back(vec[f]+1); }
        sort(ret.begin(), ret.end());
        vec = ret;
        ret.clear();
    }
    return vec;
}

void solve(vector<int> vec) {
    sort(vec.begin(), vec.end());
    vec = zero(vec);
    vec = one(vec);
    vec = zero(vec);
    vec = one(vec);

    int k = vec.size()-1;
    //for (int i = 1; i <= k; i++) cout << vec[i] << " "; cout << "\n";
    for (int i = 0; i <= k; i++) dp[i] = 0;

    dp[0] = 1;
    dp[1] = (vec[1] + 1) / 2;
    for (int i = 2; i <= k; i++) {
        ll d = vec[i] - vec[i - 1];
        if (d % 2 == 0) dp[i] = (dp[i-1] * ((d+3)/2) % MOD + MOD - dp[i-2]) % MOD;
        else dp[i] = dp[i-1] * ((d+1)/2) % MOD;
    }

    cout << dp[k] << "\n";
}

int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(0);

    cin >> n;
    for (int i = 1; i <= n; i++) cin >> arr[i];

    vector<int> vec(1, 0);
    for (int i = 1; i <= n; i++) {
        vec.push_back(arr[i]);
        solve(vec);
    }

    return 0;
}

Compilation message (stderr)

fib.cpp: In function 'std::vector<int> one(std::vector<int>)':
fib.cpp:13:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   13 |         for (int i = 2; i < vec.size(); i++) {
      |                         ~~^~~~~~~~~~~~
fib.cpp:20:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   20 |         for (int i = 0; i < vec.size(); i++) {
      |                         ~~^~~~~~~~~~~~
fib.cpp: In function 'std::vector<int> zero(std::vector<int>)':
fib.cpp:36:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   36 |         for (int i = 2; i < vec.size(); i++) {
      |                         ~~^~~~~~~~~~~~
fib.cpp:43:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   43 |         for (int i = 0; i < vec.size(); i++) {
      |                         ~~^~~~~~~~~~~~

• Subtask 1: 5 / 5
• Subtask 2: 20 / 20
• Subtask 3: 15 / 15
• Subtask 4: 10 / 10
• Subtask 5: 0 / 15
• Subtask 6: 0 / 35